# `LivePanels.Canvas.Shared.Backend`
[🔗](https://github.com/livepanels/livepanels/blob/v0.1.0/lib/livepanels/canvas/shared/backend.ex#L1)

Shared-mode backend record.

Shared mode keeps LivePanels headless while still giving applications a paved
substrate for coordinator lookup, coordinator ownership, layout persistence,
and local participant tracking. A backend describes those runtime pieces as
one unit.

Applications select a backend through `use LivePanels.Canvas`:

    use MyAppWeb, :live_view

    use LivePanels.Canvas,
      pubsub: MyApp.PubSub,
      session: [
        mode: :shared,
        backend:
          {LivePanels.Canvas.Shared.Local,
           layout_store: MyApp.CanvasLayouts}
      ]

Clustered applications can opt into an adapter such as
`LivePanels.Canvas.Shared.Horde` without changing the canvas command,
event, reducer, fanout, or persistence grammar.

# `backend_health_check_report`

```elixir
@type backend_health_check_report() :: %{
  canvas_id: String.t(),
  backend: atom(),
  distributed?: boolean(),
  process_registry: process_registry(),
  dynamic_supervisor: term(),
  participant_tracker_name: atom(),
  participant_tracker_supervisor: term(),
  layout_store: module(),
  message_families: [atom()],
  state_topic: String.t()
}
```

# `process_registry`

```elixir
@type process_registry() ::
  atom()
  | :global
  | {:global, atom()}
  | {module(), atom()}
  | {:via, module(), atom()}
```

# `t`

```elixir
@type t() :: %LivePanels.Canvas.Shared.Backend{
  adapter: module() | nil,
  distributed?: boolean(),
  dynamic_supervisor: term(),
  explicit?: boolean(),
  layout_store: module(),
  name: atom(),
  opts: keyword(),
  participant_tracker_name: atom(),
  participant_tracker_supervisor: term(),
  participant_tracker_supervisor_module: module(),
  process_registry: process_registry(),
  supervisor_module: module()
}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*